氟硅酸铵氨化制备纳米二氧化硅的实验研究

摘要

实验以氟硅酸铵和氨水为原料,通过化学沉淀法制备纳米二氧化硅粉体.考察了表面活性剂、反应温度、物料配比等不同工艺条件对纳米二氧化硅粉体的粒度分布、反应收率等的影响.实验结果表明:分散剂十二烷基苯磺酸钠可以有效改善粉体粒度的分布;综合考虑二氧化硅粉体的粒度、反应收率、反应效率和生产成本,确定氟硅酸铵氨化制备二氧化硅的反应温度为常温、反应时间为60 min、物料配比(氟硅酸铵与氨水物质的量比)为1∶4.8、氨水的加料速度为96 mL/min、搅拌速度为200～300 r/rain.%Nano silica powder was prepared by chemical precipitation method with ammonium fluosilicate and ammonia as raw materials.The effects of different reaction conditions,such as surface active agent,reaction temperature and material ratio,on the particle size distribution and yield of nano silica powder were investigated.The experimental results showed that the dispersant SDBS can effectively improve particle size distribution;considering the particle size of silica powder,the reaction yield and reaction efficiency and production cost,the conditions of silica preparation by ammoniation of ammonium fluosilicate were determined as follows:reaction temperature was room temperature,the reaction time was 60 min,the material mix ratio (amount of substance ratio of ammonium fluorosilicate to ammonia) was 1∶4.8,ammonia feeding speed was 96 mL/min and the stirring speed was at 200～300 r/min.